KR0162531B1 - Manufacture of anisotropic conductive film and manufacture of lcd panel using this film - Google Patents

Abstract

A mounting glass mask is used to expose the medium that becomes conductive when light is emitted. Thereby, the electric charge on the surface of the medium to which light is irradiated disappears through a discharge or a metal plate, and the charging pattern according to the mounting pattern can be made. Next, on the surface of the medium, conductive particles, which are materials obtained by plating a conductive material on the surface of the core insulator, are dispersed. Conductive particles are concentrated in the area where the medium is charged. When the insulating resin of the anisotropic conductive film is coated or transferred, the anisotropic conductive film in which the conductive particles are unevenly distributed in accordance with the mounting pattern is completed.

Description

Manufacturing method of anisotropic conductive film used for liquid crystal display device

1A, 1B, and 1C are cross-sectional views of the production process showing the method for producing the anisotropic conductive film of the present embodiment.

2A and 2B are sectional views of another manufacturing process showing the manufacturing method of the anisotropic conductive film of this embodiment.

3A and 3B are sectional views of still another manufacturing process showing the manufacturing method of the anisotropic conductive film of this embodiment.

4A and 4B are plan views of the glass mask of the portion shown in FIG. 1, FIG. 4A is a glass mask for exposure exposure, and FIG. 4B is a glass mask for mounting.

5 is a plan view of an anisotropic conductive film produced by the present invention.

6A and 6B are cross-sectional views of a connection portion between a liquid crystal panel and a driving IC using the anisotropic conductive film produced according to the present invention.

7 is a perspective view in which a driving IC is mounted on a liquid crystal display panel using an anisotropic conductive film prepared according to the present invention.

* Explanation of symbols for main parts of the drawings

1: conductive particles 2: insulating resin

3: medium 4: metal plate

5: glass mask 6: shading pattern

7: driving IC 8: panel

9 driving IC connection electrode 10 liquid crystal panel connection electrode

11 wiring 12 liquid crystal display panel

TECHNICAL FIELD The present invention relates to an anisotropic conductive film, and more particularly, to a method for manufacturing an anisotropic conductive film for use in connecting a lead line of a display panel of a liquid crystal display device to a driving IC.

In a liquid crystal display device, when the lead wire of a liquid crystal display panel and a tape carrier package, or a lead wire and a bare chip are connected, it connects using an anisotropic conductive film. The anisotropic conductive film is an adhesive capable of having anisotropy in conductivity. Further, in detail, metal particles such as copper and nickel are dispersed in the adhesive, and the pressure direction is applied to the portion to which the electrical connection is to be made by controlling the content, shape, size, etc. of the metal particles as necessary, and the thickness direction of the adhesive layer. Is a film of an anisotropic adhesive having conductivity, and conductivity in both directions maintaining insulation. This film can bond a large number of bonding pads at a time because the film is printed on the wiring board with the adhesive mixed with particles on the entire surface and face down bonded. In addition, the IC chip using this film has a feature that the IC chip can be reduced in price since no vamp is required. As a method of connecting an electronic component or an IC chip using this film, it is described in Japanese Patent Laid-Open No. 51-100679 or Japanese Patent Laid-Open No. 58-21350.

However, in the case of using an anisotropic conductive film for connecting an electrode such as a liquid crystal display device to an external driving circuit, when the connection density increases, insulation between adjacent electrodes cannot be maintained, and the area of the connection becomes small, contributing to the connection. There existed a problem that connection resistance became large because the number of the electroconductive particle made to become small.

Therefore, an anisotropic conductive film in which conductive particles are localized is described in Japanese Patent Laid-Open No. 3-62411 (Prior Example 1). In the method for producing the film, an adhesive is applied to a portion where conductive particles are to be collected, a grounded electrode is provided thereunder, and an insulating mask is used as necessary to mask conductive particles charged through a corona electric field. It is injected into the adhesive part which is not present, and the conductive particle is realigned.

Moreover, the manufacturing method of the anisotropic conductive film by which the electrically-conductive particle described in Unexamined-Japanese-Patent No. 60-126889 (Prior Example 2) unevenly distributed was made by irradiating light to the photosensitive resin, making hardened | cured and uncured part, and etching uncured part. To the patterned insulating pattern by corona discharge or friction with a magnetic brush, to form an electrostatic pattern, to deposit conductive particles on the electrostatic pattern portion, and then to apply an adhesive and peel off together with the conductive particles to form an anisotropic conductive film. Is to write.

Japanese Unexamined Patent Publication No. 59-191395 also describes a method for dispersing conductive particles on a substrate surface. However, this publication is a method for producing a ceramic substrate wiring for copper plating on a ceramic substrate. It has nothing to do with the act.

However, in the conventional example 1, since the electrode and the insulating layer mask formed according to the wiring pattern are required, there is a problem that fine positioning is difficult. In the conventional example 2, since the hardened | cured and uncured part is made, and the uncured part is etched while irradiating light to a photosensitive resin, a process is complicated.

An object of the present invention is to produce an anisotropic conductive film in less steps.

In the anisotropic conductive film of the present invention, a step of providing a medium that changes from insulating to conductive by irradiation of light, a step of selectively irradiating light to the medium, and a step of ubiquitous conductive particles in a portion to which the light of the medium is irradiated And a step of forming an insulating layer on the medium and including conductive particles in the insulating layer.

In the method of ubiquitous the conductive particles, the entire surface of the insulating medium is charged, and selectively exposed using a predetermined glass mask to eliminate charges on the surface and inside of the region to which light is irradiated, and It characterized in that the conductive particles charged with the opposite charge on the medium by ubiquitous by electrical attraction.

The predetermined glass mask may be a glass mask for exposure, but is characterized by using a mounting glass mask in which light-transmissive conductive wiring is formed.

The medium is characterized in that the polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE).

The conductive particles are characterized by being a substance in which a conductive material is plated on a surface that is a core insulator.

As shown in FIG. 1, the medium 3 on the metal plate 4 such as copper, for example, polyethylene terephthalate (PET) or polytetrafluoroethylene (PTFE) (white translucent) is about 20 It is formed in the thickness of micrometer. This PET and PTFE have the property that the part which does not emit light shows insulation, and when it emits light, it shows electroconductivity. This medium (3) has the advantage that the price is cheaper than that of the conventionally used photosensitive resin. The metal plate 4 is grounded, and its thickness is 100 micrometers or more. The medium 3 is charged by the surface or the inside using corona discharge or the like, and a case of positive charging is shown in FIG. 1A. The charge amount is about 0.5 KV at the surface potential. This game may be sound.

Next, as shown in FIG. 1B, light is irradiated to the medium through the glass mask 5 having a thickness of about 1.1 mm. The medium 3 is exposed, so that the exposure area 30 is changed into a conductive material, and the charge on the surface or inside disappears through the metal plate 4 when discharge or light enters the inside of the medium. As a result, a charge pattern is formed like the pattern of the glass mask 5.

As the glass mask 5, the glass mask shown in FIG. 4A and FIG. 4B is used. 4A is a glass mask 5-1 for exposure only. On the glass mask 5-1, the light shielding pattern 6 is formed in accordance with a mounting pattern, for example, a bonding pattern. The light shielding pattern 6 is made of chromium having a thickness of 300 nm and does not pass light. Therefore, only light transmitted through portions other than the light shielding pattern 6 is scattered on the surface of the medium 3. In addition, this application uses the mounting glass mask 5-2 shown in FIG. 4B. This glass mask 5-2 is a glass mask for mounting as a finished product in which all the wiring necessary for a liquid crystal display device is laid, and the transparent conductive pattern 11 which consists of a light shielding pattern and ITO is formed. These ITO wirings are connected to the gates and the drains of the memory cells, respectively, as drive lines and lead lines of the liquid crystal panel. On the output side, since high resistance may be sufficient (for example, 1 KPa), high resistance ITO can be used sufficiently. On the other hand, on the input side, the gate wiring is made of metal such as chromium and connected to the ITO wiring in a region other than the anisotropic conductive film. Since the mounting liquid crystal panel also serves as an exposure mask, it is not necessary to create an exposure glass mask for each mounting pattern and the cost can be reduced.

Next, as shown in FIG. 1C, conductive particles 1 having an average diameter of 5 μm are charged onto the medium 3 having the charge pattern formed thereon. The conductive particles are charged opposite to the medium (3), in this example negatively charged. The conductive particles are obtained by plating conductive materials such as nickel and gold on the surface of the core insulator. Therefore, the conductive particles can be more easily charged than other metal spheres. The conductive particles 1 gather into a portion where the medium 3 is charged by electrical attraction. An insulating resin 2 having a thickness of about 20 μm is coated thereon to form an anisotropic conductive film having conductive particles unevenly distributed in a specific mounting pattern as shown in FIG. 2 or transferred and shown in FIG. 3. In the case of applying the insulating resin 2, the paste-type insulating resin 2 is applied onto the medium 3 and the conductive metal 1 of FIG. 1C with a dispenser or the like. At this time, the paste-type insulating resin 2 is widened to surround the conductive metal 1, and FIG. 2A is formed. Thereafter, as shown in FIG. 2B, the anisotropic conductive film is removed from the substrate 3. When transferring the insulating resin 2, the insulating resin 2 shown in FIG. 3A is made into a film form on a base film with undried. It is placed on the medium 3 and the conductive metal 1 of FIG. 1c and lightly pressurized. Since the insulating resin 2 is in an undried state, the conductive metal 1 enters the inside of the film-type insulating resin 2 and adheres to the surface to form the third drawing. 5 is a top view of the completed anisotropic conductive film shown in FIG. 2B or 3B.

Next, a method of connecting the liquid crystal display panel and the liquid crystal driving IC using the anisotropic conductive film of the present invention will be described with reference to FIG. As shown in Fig. 6A, the driving IC connection electrode 9 is formed in the driving IC 7 with a height of about 20 mu m. On the other hand, the liquid crystal display panel 8 is the above-described mounting glass mask 5-2, in which a liquid crystal panel connection electrode 10 having a height of about 300 to 400 mm is largely aligned with the driving IC connection electrode 9. It is formed toward. The liquid crystal display panel 8 and the driver IC 7 are connected to each other with an anisotropic conductive film 2 having a thickness of about 25 to 30 μm interposed therebetween. At the time of connection, pressurization and heating are performed. Then, the thermosetting epoxy resin, which is the anisotropic conductive film 2, becomes liquid as it is heated by heating at about 150 ° C., and the gap between the liquid crystal panel connection electrode 10 and the driving IC connection electrode 9 is maintained. Spread out And as time passes, an epoxy resin will solidify completely. By the pressurization, the liquid crystal panel connection electrode 10 and the drive IC 9 are electrically connected to each other via the conductive particles 1 of about one layer as shown in FIG. 6B. The insulation between the electrodes, which is almost completely sealed with epoxy resin between the electrodes, is maintained. As shown in FIG. 7, a further liquid crystal display panel 12 is provided on the surface of the liquid crystal display panel 8 so as to be in contact with two sides while being smaller than this liquid crystal display panel. This liquid crystal display panel 12 is a liquid crystal display part. The elongate anisotropic conductive film 2 is provided in the part exposed as the outer peripheral part of the liquid crystal display panel 8. A plurality of driving ICs 7 are formed on the anisotropic conductive film 2, and electrical bonding with the liquid crystal display panel 8 is performed, respectively. The driving IC formed on the peripheral side of the liquid crystal display panel 8 is mainly an IC for gate control of the liquid crystal matrix, and the driving IC formed on the long side is an IC for controlling the leader line of the liquid crystal matrix.

In addition, this invention is not limited to the said Example, It can change and implement variously in the range which does not change a summary. For example, although the content was advanced to 6 the number of electrodes of an IC chip, it does not limit to this naturally.

In addition, the wiring 11 on the glass matrix does not need to have the shape shown in FIG. 4B.

As described above, according to the present invention, since the conductive particles are ubiquitous in accordance with the mounting pattern, for example, even if the pitch of the liquid crystal panel leader and the driving IC are narrow, even at a narrow pitch of 100 μm or less, the high insulation between the poles and the connecting portion The low resistance of becomes possible. This reduces the inter-short and terminal connection defects from 10% to 1% and from 1% to 0%, respectively, enabling high connection reliability at a narrow pitch of 100 μm or less, and high yield. In addition, since the anisotropic conductive film of the present invention uses a medium that becomes conductive when light is emitted as the insulating property, an insulating area and a conductive area can be created by only light is emitted, and the number of steps is reduced. Moreover, since the anisotropic conductive film of this invention uses PET and PTFE as a mediator, there exists an advantage that it is completed cheaper than the photosensitive conductive film. Moreover, since the anisotropic conductive film of this invention uses the mounting glass mask which formed the wiring pattern in the exposure transparent film at the time of exposure, it is not necessary to prepare the exposure glass mask on purpose, therefore cost is reduced and it is a precise mask. You can create a pattern. Moreover, since the electrically conductive particle used by this invention plated the insulator at the core and the electroconductive substance on the surface, it also has the effect of being easy to charge.

Claims (11)

Providing a medium that changes from insulating to conductive by irradiation of light, selectively irradiating light to the medium, spreading conductive particles in a portion to which the light of the medium is irradiated, and Forming an insulating layer and including the conductive particles in the insulating layer. Through the process of providing a medium that changes from insulating to conductive by irradiation of light, the process of charging the entire surface of the medium to one electric charge, and the glass mask patterned in a predetermined pattern, the medium is irradiated with light, Charging the charge and leaving the uncharged portion charged; localizing the conductive particles charged to the opposite charge on the medium of the charged portion; and insulating layer on the medium And forming the conductive particles in the insulating layer. Through a step of forming a medium that changes from insulating to conductive by irradiation of light, a step of charging the entire surface of the medium, and a mounting glass mask in which a predetermined pattern is formed of a first light-transmissive portion and a second light-transmissive portion And irradiating the medium with light, discharging the charge of the splitted portion, and charging the unlit portion with the charged state, and conducting particles charged with opposite charges on the medium of the charged portion. And forming a insulating layer on the medium and incorporating the conductive particles into the insulating layer. The method for producing an anisotropic conductive film according to claim 1, wherein the conductive particle is a material obtained by plating a conductive material on the surface of the core insulator. The method of claim 1, wherein the medium is polyethylene terephthalate or polytetrafluoroethylene. In the liquid crystal panel manufacturing method which connects the electrode of a liquid crystal panel and the electrode of a drive element with an anisotropic conductive film, The manufacturing method of the said anisotropic conductive film includes the process of forming the medium which changes from insulation to electroconductivity by light irradiation, and Selectively irradiating light to the medium, dispersing conductive particles in the portion to which the light is irradiated, forming an insulating layer on the medium and including the conductive particles in the insulating layer. The manufacturing method of the liquid crystal panel characterized by having. The liquid crystal panel according to claim 6, wherein the medium is irradiated with light to the medium using the liquid crystal panel as a mask, and a portion of the liquid crystal panel electrode is not transmitted through light, and other portions of the liquid crystal panel transmit light. A method for producing a liquid crystal panel, characterized by changing the conductivity. The method for producing an anisotropic conductive film according to claim 2, wherein the conductive particle is a material obtained by plating a conductive material on the surface of the core insulator. The method for producing an anisotropic conductive film according to claim 3, wherein the conductive particles are materials obtained by plating a conductive material on the surface of the core insulator. The method for producing an anisotropic conductive film according to claim 2 or 8, wherein the medium is polyethylene terephthalate or polytetrafluoroethylene. 10. The method for producing an anisotropic conductive film according to claim 3 or 9, wherein the medium is polyethylene terephthalate or polytetrafluoroethylene.